Yes, Dale, it is no problem to use the GriffinPower Mate with Flex. I like it to use it too also in parallel with the K6TU App on my IPad. So I can tune two slices without jumping with the mouse from One to the other slice.
If you Need More Infos how to configure the GriffinPower Mate don't hesitate to ASK me.
Norbert, dj7jc@t-online.de

These documents are for PowerSDR. I no longer have a PowerMate so I can't verify that they would work with SmartSDR. SmartSDR does not have the feature of mapping keyboard key combinations to commands which is what the PowerMate uses so I am not sure if it will work with SmartSDR.